1. Field of Invention
The present invention relates generally to torsional vibration dampers and more specifically to such dampers employed in power transmissions having hydrokinetic torque converters.
2. Description of the Prior Art
While mechanisms for damping the torsional vibrations delivered from automotive engines to vehicle drive trains have long been known in the art, their use has heretofore been primarily limited to manually clutched transmissions. Damping has been effected in automatic transmission systems by the hydrokinetic torque converters typically employed. With present day attempts to improve vehicle fuel economy, however, automatic transmissions frequently have modes of operation in which the torque converter section is mechanically locked up to prevent power waste due to slippage in direct drive. During such modes of operation, a torsional isolator or damper must be provided; and the prior art designs are not directly adaptable to serve this purpose, since they have been insufficiently compact to permit their required installation within the automatic transmission. They have also been objectionably expensive for this purpose.